The calculated radiative cooling rate coefficient for krypton as a trace impurity in low to moderate density plasmas is calculated. Collisional-radiative line emission, dielectronic recombination, radiative recombination and bremsstrahlung are considered as the principal radiative loss channels. Collisional-radiative models and the calculated charge state distribution for krypton have been benchmarked against measured ion brightness profiles in the FTU plasma. The calculated radiative loss rate is compared with two measurements of the radiative cooling coefficient for krypton in the FTU plasma. The measurements differ in how the krypton density profile is experimentally constrained. The krypton density profile is found (to be flat) from spectroscopic observations and (to be increasing radially outwards) from measurements of visible bremsstrahlung emission. The calculations show excellent agreement with the former set of measurements. Polynomial fits to the total radiative cooling coefficient are provided for ease of use in plasma modelling codes. Tables of ion emissivities are provided for use in modelling radiative losses from non-equilibrium plasmas.
Calculation of the radiative cooling coefficient for molybdenum in a low density plasma